Synthetic Diamond, Its Properties and Synthesis

Abstract

ABSTRACTThe synthesis of crystalline diamond in the Soviet Union, Japan, and the United States is reviewed. A comparison of the various growth techniques is presented. Hydrogen and its role in the synthesis process has been controversial; a model is presented illustrating its essential, but limited role. Another controversial aspect of diamond synthesis concerns the nature of the carbon bond in the reactant gas and how this influences the resultant crystal; an heuristic model is provided. Non-thermal equilibrium growth techniques are generic to the recent advances in diamond growth; the separation of the process for the disassociation of the reactant gas from that of the “surface cleaning” and the artificial stimulation of the surface migration velocity may be absolutely necessary for defect-free nucleation and growth. While the various properties of diamond have been known long before the advent of artifact diamond, its potential for use in devices has only recently been modelled and calculated; numerical figures of merit are compared with those of other semiconducting materials. Charge carrier velocity profiles of diamond are compared with those of more conventional semiconductors. Strengths and weaknesses accruing from the diamond velocity profile are addressed.